Means for attaching a union nut or the like to the end of another member



Feb 6, 1940. i Q M, CAR|NGTON 2,189,056

MEANS' FOR ATTACHING A UNION NUT OR THE LIKE TO THE END OF' ANOTHERMEMBER Filed May 6, 1938 YMmmmM.

Patented Feb. 6, 1940 l y l :e

I MEANS ATTACHING A UNION OR THE LIKE T'O` THE' END OF ANOTHER y MEMBERCharles Molyneux .Carington, London, England, assignor to. K. L. G.Sparking Plugs Limited, London, England, aBritish company ApplicationMay 6, 1938, 'Serial No. 206,489

v In Great Britain June 23, 1937v 1y Claim.r (Cl. 287-91) This inventionrelatesl to an improved joint .between a union nut and an inner memberwhereby the inner member may bev joined by ameans of the nut to the endof a thirdmember. Where the nut has an inwardly-directed flangeconvenient. y l According 'to the invention, a joint between a union nutand an innermember with respect to which a nut is rotatable comprises aninternal flange4 on the nut and an 4external flange on the inner member,said external ange having a larger diameter than said internal flange,Aandr a split washer substantiallyvsurrounding,the'yinner member andlying between the adjacent faces of the two flanges so as to preventendwise separation between the nut and theA said inner member. Aspecicembodiment of the invention lwill now be described, by way of example,as applied to the 4joining of two parts of the tubular casing Ienclosing the high-tension lead of the ignition system ofaninternal-combustion engine.y In the accompanying drawing:

Figure l is an elevation, partly in section, of a coupling for housingthe conductor which connects Aa. sparking-plug to the magneto,

Figure 2 is an outside elevation at right-angles to Figure 1,

Figure?, is a section on the line 3-3 of Figure 1, showing certain partsrelatively angularly displaced,

Figure 4 is a section on the linel 4-4. of Fig ure 1, and

Figures 5 and 6 are diagrammatic perspective views to explain the methodof assembly.

As shown in Figures 1, 2, 3 and 4, the coupling comprises a horizontallimb IIJ, a spherical enlargement II at the corner, and adownwardlyextending limb I2. The elbow is lined with a moulding ofsynthetic resin of which agcylindryical portion I3 protrudes downwardlywithin a metal tube I4 which is `lined with insulating material (notshown). The tube I4 forms an upward extension from the body of asparkingplug (not shown), and the apparatus illus'- trated in thedrawing serves the purpose of i 'connecting the high-tension cable fromthe magneto electrically and mechanically to the sparking-plug and offorming a continuous metallic screen from the body of the sparking-plugto the metal braiding surrounding the cable; the screen thus formedprevents the emission of radiations which might interfere with radioreception and excludes Water and other foreign matter from access to theelectrical conductors within the lining I3 and the tube I4.

The elbow I0, I2, and the tube I4, are held together by a nut-memberwhich comprises a central screw-threaded portion I5, an outer knurledsleeve I5 and an intermediate ring I1. The ring II is Wrapped, as astrip of metal, around a groove in the central portion I5 and thesleeveis lthenpressed. on from the top (as seen in the drawing) so as tomake tight engagement with serrations I8 formed on the portion I5 abovethe groove aforesaid whereby the ring I 'Iis imprisoned between theslee-ve and the portion I5. The ring II is formed with twodownwardly-extending fingers I9 each of which is pressed with a ridge 20at its lower end to engage teeth 2|' formed on the tube I4. Thenut-member is thereby locked against rotation on the tube I4 exceptwhen'force is deliberately applied to the sleeve .|I.-` y

. The limb` I2 of themetal elbow is formed at its lower end (see alsoFigures 5 and 6) with an outwardly-directed flange which is cut away soas to leave three castellations 22 each of approximately sixty degreesin angular extent `and each spaced by an interval of sixty degrees fromthe next. The top of the screw-threaded portion I5 of the nut-member isformed with an inwardly-directed flange which is cut in exactly the sameway, so as to leave three symmetrically arranged inwardly-directedcastellations 23 each of sixty degrees in angular extent. The angularextent of each of the six castellations 22 and 23 is, in fact, slightlyless than sixty degrees so as to permit one set of castellations to passthrough the gaps between the others, as described below.'

It will be seen that the spherical portion I I of the metal elbow is toolarge to permit the nutmember-to be passed along the limb I0 into theposition it occupies in Figure 1 and that the portion II is so near tothe castellations 22 that it is impossible to form a flange at the topof the nut-member after the nut-member has been placedin that position.According to the invention, therefore, the nut-member is ilrst slidalong vthe limb I2, by engaging the castellations Il y x ist `23 withthe gaps between the castellations 22, until the castellations 23abutagainst the spherical portion Il. A split steel washer 24 is nowinserted into the gap between the two sets of castellations.

The manner of assembly will be more-clearly vunderstoodfrom the diagramsof Figures 5 and 6. The washer 24 is first distorted into a helix, one

end of which isinserted behind one of the casv tellations 22 and thehelix thenrotated until the washer lies wholly behind .the castellationsasA shown in Figure 5. The nut-'member is nowslid on to the limb I2, thecastellationsl 22 passing through the gaps between the castellations 23,until the castellations 23 lie between the washery 24 and thecastellations 22; the space between the castellations 22 and the washer24 isexage;

gerated in Figure 5, for the purpose of clearness. One end of the washer24 is now pressed down,

20 as shown in Figure 6, into the gap betweenl a castellation 23 and acastellation 22. K The washer, isthen rotated until it lies `whollybetween the two sets of castellations, as shown in Figure l. Thenut-member may now be screwed on to the tube I4; preferably the top ofthe tube is sepag tellations 22 on to the limb l2 is not illustrated`arated from the castellations 22 by an aluminium washer 25. n

The. manner in which the washer 24 has to be deformed in order to bepassed beyond the casin the drawings but will be clear from .thedescriptionv givenl above ofthe similar operation of lscrewing thewasher into the space between the two sets of castellations 22, 23.

The elbow lil, l2, may be rotated to any convenient position before thenut-member is tightened andthecastellations 22, 23, and the gap 26 inthewasher 2d will ordinarilyv al1 be out of register with one another asshown in Figure v3.

4m Should one set of castellationslie exactly in register with the gapsbetween the vcastellations in the otherset, the washer 24 resistsseparating forces between `the two parts l2 and l5 byshear stress. Suchstress will occur at ,six `lpoints' around, the washer except where .theIgap 2 6`in the washer happens to lie exactly between `the endy of onecastellation 22 and the adjacent en d of the next castellation 23; inkthis postonlhe washer is stressed'atonlyve points andit is clear thatthe number of such points of stress can never, in any circumstances, beless than five.

The number of castellations in each set 22, 23

is preferably such that, on the one hand, the washer 24 will be in shearat as manypoints as possible when'jthe castellationsv inoneset lieexactly opposite the gaps between the castellations in the other setand, on the other hand,

v'ithere is a gap in each flange of suicient size to permit thetting lofthe washer into position yin Figures 5 and `6-.l Although, in theexample described above with reference to the drawing, there are threecastellations in -each flange, a larger number ofcastellations might beprovided An advantage of the invention is that portion l5 of thenut-member may be smaller thanthe external diameter of the castell-atedflange?? on the limblZ; in this way theinventionvgives a more compactarrangement thanis 'possible with union nutsl of ordinaryconstru'c- Ajoint, between'a union nut and'fani-nner 'n member with-respect to whichthe nut is rotatable, comprising an outwardly-directed .Y castellatedflangev on the inner member lying-behind an inwardly-directedcastellated flange .onV the nut, the external diameter of the Aflange`on the inner member being greater than the internal diameter `of theflange on the nut and the castellations of each flange being capable ofpassing through gaps between, the castellations of the other,'anda'split washer substantially surrounding the inner member and'lyingbetween thefadendwise separation between the nut "and the jacent facesof the two flanges so as to prevent initierV member.

` CHARLES vl\`/1C)L`SZ"NEUX CARINGTQN.

1t..-y the manner. described above with reference to 15 ywhere theinvention is 'to be applied to a joint f o between members of largerdiameter. i the internal diameter of the screw-threads in the `0

